Source : Webster's Revised Unabridged Dictionary (1913)

Asphyxiate \As*phyx"i*ate\, v. t.
   To bring to a state of asphyxia; to suffocate.

   Note: [Used commonly in the past pple.]

Source : WordNet®

asphyxiate
     v 1: deprive of oxygen and prevent from breathing; "Othello
          smothered Desdemona with a pillow"; "The child
          suffocated herself with a plastic bag that the parents
          had left on the floor" [syn: {smother}, {suffocate}]
     2: impair the respiration of or obstruct the air passage of;
        "The foul air was slowly suffocating the children" [syn: {suffocate},
         {stifle}, {choke}]
     3: be asphyxiated; die from lack of oxygen; "The child
        suffocated under the pillow" [syn: {suffocate}, {stifle}]